20801 2013-01-29 06:06:42 +0000 [Custom]: Custom element generation algorithm should be careful about its argument 2013-02-14 22:39:52 +0000 1 1 1 Unclassified WebAppsWG HISTORICAL - Component Model unspecified PC All RESOLVED DUPLICATE 20686 P2 normal --- 17103 1 morrita dglazkov public-webapps-bugzilla oldest_to_newest 82262 0 morrita 2013-01-29 06:06:42 +0000 In Section 4, custom element constructor generation algorithm, Step 5: > "Set CONSTRUCTOR as the constructor property on PROTOTYPE." If the PROTOTYPE is a built-in object like HTMLSpanElement.prototype, the algorithm overwrites its "constructor" property, which isn't good. 82679 1 morrita 2013-02-07 03:29:36 +0000 I think that we should just forbid which has "constructor" property for the prototype parameter. That means we cannot use HTMLSpanElement as an default. The default will be then something like Object.create(HTMLSpanElement.prototype). 82717 2 dglazkov 2013-02-07 21:47:30 +0000 I see what you're saying. If the user passes in an object that is already in the middle of a prototype chain, the algorithm will be breaking it. 82727 3 morrita 2013-02-08 01:17:26 +0000 hat you're saying. If the user passes in an object that is already in > the middle of a prototype chain, the algorithm will be breaking it. Right. Basically, we shouldn't overwrite any existing properties. 83163 4 dglazkov 2013-02-14 22:39:52 +0000 Merging this bug with 20686. *** This bug has been marked as a duplicate of bug 20686 ***